Hydraulic apparatus for broaching



1933- G. .I. RUSSELL.

HYDRAULIC APPARATUS FDR BROACHING 3 Sheets-Sheet l Inventor r 6 :[Russ ZZ- Filed March 5, 1930 NOV. 21, 1933. J RUSSELL 1,936,073

HYDRAULIC APPARATUS FOR BROACHING Filed March 5, 1930 3 Sheets-Sheet 2 :3

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Nov. 21, 1933.

M! l I G. J. RUSSELL 1,936,073

HYDRAULIC APPARATUS FOR BROACHING Filed March 5, 1930 3 Sheets-Sheet 3 Invento 6607922USS6ZL b mow 4% 3% A zt 'ys.

Patented Nov. 21, 1933 1 UNITED STATES PATENT OFFICE 1,936,073 HYDRAULIC APPARATUS FOR BROACHING George J. Russell, Waltham, Mass. Application March 5, 1930. Serial No. 433,490 lclaims. (01. 90-33) This invention relates to broaching machines of the type wherein the material or stock to be broached is moved relative to the broach, while the latter remains substantially stationary during the broaching operation. In machines of this general class, the broach seats against an abutment which is removable to permit discharge of finished stock from the broach. The means for moving the stock relative to the broach, the broach itself, and the movable abutment require certain minimum space longitudinally of the apparatus, and more or less determine the minimum spatial requirements for machines of 1 this character. Mechanism for imparting rcciprocatory motion for advancing stock during the broaching process has heretofore required additional space longitudinally of such machines.

Moreover, in machines of this general class it is desirable to have apparatus capable of moving the stock along the broach with a substantially uniform motion and also at speeds which may be varied as conditions may require. For these purposes fluid pressure means, such as power cylinders, are satisfactory. In some aspects the invention relates to the arrangement and com struction of power cylinders. While these feae tures are particularly desirable in broaching machines they also have more general application in various other types of hydraulic machines.

Objects of the present invention are to improve the construction and arrangement of parts of broaching apparatus of the class described so that such apparatus will occupy less space longitudinally; to provide a compact nested arrangement of parts for broaching apparatus of simple and efficient, and yet strong and durable construction; to provide broaching apparatus of the class described with fluid'pressure mechanism for advancing the stock to be broached; to provide an improved construction for incorporating fluid pressure means, such as power cylinders, in broaching machines of the class described; and also to provide improved means for operating the movable abutment'or pilot which engages the rear end of the broach.

In accordance with the present invention, fluid pressure means, such as power cylinders, may be disposed at the rear end of the broach, preferably on either side of the movable abutment against which the breach rests during the broaching operation. By arranging power cylinders in this manner and providing suitable connections to the reciprocatory means which advance the stock-to be broached, the power cylinders may be I embodied in a broaching machine of this class without appreciably increasing the spatial requirements. The power cylinders preferably are mounted on the bed plate of the machine, the heads of the cylinders being formed in relatively fixed and movable abutments between which the cylinder walls are clamped by tension members. These tension members preferably connect the fixed abutments. with a backing or equalizing plate which seats on another'fixed abutment and carries compression members arranged to transmit forces to the movable cylinder head at points within the longitudinal projection of the cylinder walls. This avoids imposing unequal or torsional stresses upon the cylinder walls and provides a rugged compact construction for holding the walls and the cylinder heads in place. Furthermore, the parts are so arranged and constructed that the cylinders may readily be dismantled or assembled.

In the drawings:

Figs/1 and 2 are top plan views'of a broaching machine showing movable parts in different positions;

Fig. 3 is a sectional elevation of the broaching machine shown in Figs. 1 and 2, showing the backcenter in elevation;

'Fig. l is an elevational view of a cylinder head; and

Fig, 5 is a section taken substantially along the line 5 -5 Of Fig. 4.

In the apparatus selected for illustration an internal broaching tool 10 is supported at its rear end in previously broached pieces of stock 11, which pieces are movable through a passage 12 in a transverse member 13 mounted upon the bed plate or foundation structure 15 of the machine. At the rear end of the broach a movable abutment or pilot 14 is shown in withdrawn position in Fig. 3, in which position stock previously broached is permitted to drop or fall off the forward end of the broach into a chute 16 from which it may be removed from the machine. Material or stock to be broached is advanced from right to left (Figs. 1 to 3) along thebroach by movement of the cross-head 17 which is mounted in ways '18 disposed longitudinally at the sides of the machine, as shownin Figs. 1 and 2. After the stock to be broached has been centered in the stock carrier and advanced over the rear end of the broach, the front-center 19 is moved forward to engage this end of the broach to center the same during the continued advance the cross-head returns from left to right, it will 10 be understood that the front-center is withdrawn to permit another piece of material or stock to be placed over the front end of the broach. The movable abutment or pilot 14 at the rear end of the broach is arranged to engage the latter preferably only during forward movement or" the cross-head 13, and after this forward movement has been completed or at some time during the return stroke of the cross-head, this movable abutment is withdrawn or disengaged from the rear end of the-broach. This abutment may be withdrawn on each return stroke of the crosshead or the abutment may be withdrawn only after several pieces of material have been broached and have accumulated upon the abutment member.

This abutment or pilot member comprises a rod which may be cylindrical, as shown, and arranged to operate slidably through an opening 21 provided in a vertically disposed plate 22 which is in any approved manner to a transverse member 23 mounted upon the foundation structure. This transverse member is provided with a longitudinal passage 24 adapted to provide a bearing or to'serve as a guideway for the rod 26 of a reciprocating head 27. The pilot member is provided at its rear end with a threaded extension 28 by which it is connected to a tapped and threaded recess in the forward end i the head 27; and to facilitate connecting these parts the rear end of the pilot member may be in the form of a nut 29, as shown. The head 27 operates in a cylinder 31 which is mounted in another transverse member 32 carried by the bed to the transverse frame plate. A pitman rod 33 is pivotally connected to the head 27 and to a crank 34 mounted upon a pin 36 which is carried in bearings 38 afiixed to a stationary part of the apparatus,'preferably member 13 as shown in Figs. 1, 2 and 3 of the drawings. The lower portion of the crank arm is in the form of a gear sector 39 which meshes with a longitudinally slidable rack 41. This rack carries at the rear end a depending lug 42 which is apertured to fit over the reduced end portion of a piston rod 43', the lug being aihxed to the rod by means. of nuts 44. This piston rod is connected to a piston 46 which operates in an auxiliary cylinder comprising a casting 47 having a cylindrical bore, one end of which is closed by a threaded plug 48 and the other end of which is provided with a removable head 49 having an annular recess to receive the annular ledge 51 formed on the end of the casting. The head 49 carries the gland 52. and packing 53 for the piston rod. This cylinder is provided with ports 54, 56 for admission and discharge of operating fluid. The upper exterior surface of this cylinder preferably is arranged to serve as a guideway for the rack. It will be understood that by operating the piston 46 in this auxiliary cylinder the rack and gear sector may be operated to advance and withdraw the removable abutment 14 as desired. On withdrawal of the pilot the vertically disposed plate through which the pilot moves is effective to remove pieces of broached stock in the event that these pieces tend to remain on the pilot.

The fluid pressure means for operating the crosshead 17 comprise horizontal cylinders 61 disposed preferably on each side of the movable abutment and the mechanism for operating the same. Pistons 62 (Figs. 1, 2, 4, and 5) working in these cylinders are connected to piston rods 63 and these in turn have reduced ends which are secured in longitudinally disposed holes in the cross-head 17 by means of nuts 64 threaded upon the outer ends of these rods. It will be apparent that as the pistons reciprocate in the cylinders the cross-head will be advanced and withdrawn.

The detailed construction of the horizontal cylinders 61 is shown in Figs. 4 and 5, from which it will be seen that they comprise cylindrical walls 66 which are mounted between a fixed abutment comprising the transverse member 13 mounted on the bed plate and a movable abutment or head 67. Both the fixed and movable abutments have fluid chambers 68 and ports 69 formed therein. These abutments members also have annular recesses 71 adapted to register with and to receive the end walls and the cylinders. The fixed abutment is provided with a for the rod 63 as'is usual. The movable abutment or head 67 is slidable longitudinally in a passage or guideway 73 formed in a transverse member 74 which is rigid with the foundation structure. A backing or equalizing plate '26 has its forward esge recessed to fit against the rigid member and to close this end of the passage 73 with which the movable abutment cooperates. This backing plate 76 is held on its seat'by a number of longitudinally disposed tension members, such as the rods 77, on the threaded ends of which nuts 78 are mounted to engage respectively the backing plate 7S and the fixed abutment member l3. These nuts may be countersunk in the fixed abutment as shown. The movable abutment or head 67 is provided with passages 9 to receive the tension rods and these passages also serve to prevent rotary movement of the movable head.

The backing plate 76 also carries a number of compression members shown in the form of adjusting screws 81 threaded through the plate and arranged to seat against hardened inserts in recesses 82 disposed in the movable head at points directly opposite the end walls of the cylinder 66. These compression members are adjustable through the equalizing plates and are equipped with lock or jam nuts 83 by which they may be aiiixed in adjusted positions. The tension members serve to transmit stresses from one end of the cylinder to the other during the working strokes of the piston and these stresses are transmitted through the compression members tothe movable head at points directly opposite the end walls of the cylinder. It will be apparent that by properly adjusting the tension members and the compression members, the stresses may be equally distributed throughout this portion of the apparatus so as to avoid imposing any unequal or tortional stresses upon the walls of the cylinder.

It will also be seen that the strains produced by the broaching operation are taken by the tension members 7 7 and the stresses so produced are distributed throughout the cylinder construction.

These tension members therefore serve not only as tie rods to-hold the cylinders in assembled relation but also function to distribute the working stresses.

This makes it possible to use amuch lighter frame and to provide a rugged durable construction without the use of tierods which have heretofore been necessary.

I claim: 1

1. Apparatus of the class described comprising a transverse support, means providing cylinder heads rigid with the support and similarly disposed to cooperate with cylinders disposed on one side of the support, cylinders associated with the cylinder heads on this side of the support and gland and packing 72 rigidly connected to the support, a stock carrier on the other side of the support and movable toward and from the latter for advancing stock for engagement with a tool, means for transmitting power from the cylinders to the stock carrier for actuating the latter, the transverse support having a tool receiving passage extending therethrough between the cylinders, a movable abutment disposed between the cylinders, this abutment being movable to a position to engage a tool disposed in the tool receiving passage for holding the tool from movement through the passage, and releasable means for holding the abutment in this tool engaging position.

2. Apparatus of the class described comprising a transverse support, laterally spaced and similarly disposed power cylinders arranged on one side of the support and rigidly connected thereto, a stock carrier on the other side of the support and movable toward and from the latter, means for transmitting power from the power cylinders to the stock carrier for actuating the latter, the transverse support having a tool receiving passage extending therethrough between the power cylinders, an abutment between the power cylinders, means for supporting the abutment for movement into and out of engagement with a tool in the toolreceiving passage, and an auxiliary cylinder disposed substantially between the power cylinders for actuating the abutment.

3. Apparatus of the character described comprising transverse members, power cylinders extending longitudinally between the transverse members, a stock carrier operable by the power cylinders for advancing stock to be broached, abutment means carried by one of the transverse members, the abutment means being movable into a fixed position, for receiving the reaction of the broach during broaching, the other of the transverse members providing a fixed head for each cylinder, a movable head for the other end of each cylinder, and tension means for holding the movable heads on the cylinders and for transmitting stresses between the transverse members, whereby the reaction of the broach against the abutment means may be opposed through the tension means to the reaction against the fixed heads of the cylinders during the working stroke thereof.

4. Apparatus of the class described comprising transverse members, power cylinders extending longitudinally between the transverse members, a stock carrier operable by the power cylinders and movable toward one of the transverse members for advancing stock to be broached, abutment means in pressure transmitting relation with the other of the transverse members and disposed substantially between the cylinders for receiving the reaction of the broach during broaching, said one of the transverse members providing a fixed head for each cylinder, a movable head for the other end of each cylinder, tension rods disposed about each cylinder and connected to said one of thetransverse members, means for transmitting stresses through the tension rods between the latter member and said other transverse member and the movable heads, whereby the reaction of the broach against the abutment means may be transmitted through the tension rods to oppose the reaction against the fixed heads of the cylinders during the working stroke thereof.

GEORGE J. RUSSELL. 

